Route Generation System, and Autonomous Travel System Causing Work Vehicle to Travel Along Route Generated Thereby

ABSTRACT

In a route generating system a work vehicle setting unit sets a vehicle information on a tractor. An altitude information obtaining unit obtains altitude information on a field where an autonomous travel route is to be generated. A traveling direction setting unit sets a traveling direction of the tractor in the field. A region setting unit sets, in the field, a plurality of regions including a work region where autonomous work paths in parallel with the traveling direction are generated and headlands where connection paths each connecting corresponding ones of the autonomous work paths are generated. The region setting unit sets the widths of the headlands (headland widths) based on the vehicle information, the altitude information, and the traveling direction, the widths of the headlands extending in parallel with the traveling direction.

TECHNICAL FIELD

The present invention relates to a route generating system and anautonomous travel system causing a work vehicle to travel along a routegenerated by the route generating system.

BACKGROUND ART

Heretofore, there has been known a route generating system forgenerating a route along which a work vehicle performs autonomoustravel. Patent Document 1 (hereinafter, referred to as PTL 1) disclosesthis type of route generating system (travel route generating device).According to the travel route generating device of PTL 1, work-fieldshape measuring means measures a three-dimensional shape of a field.Based on the information on the measured three-dimensional shape of thefield, data of a planned travel route for causing a work vehicle totravel in the field is generated.

The travel route generating device of PTL 1 determines an inclinationof, e.g., the entire field based on the information on the measuredthree-dimensional shape of the field. Thus, the travel route generatingdevice of PTL 1 can set the planned travel route for the work vehicle inconsideration of the fact that a work width, in which a work machineperforms work, is narrower on the surface of the inclined work fieldthan a width in a plan view. PTL 1 states that this configuration canreliably prevent a disadvantageous situation as below. That is, in acase where a work route is set on the field simply based on the workwidth of the work machine viewed in a plan view as in a conventionalway, a work width in which work is actually performed is smaller than awidth in which the work is ought to be performed on the work region.This may result in an unworked region formed in the boundary betweenadjacent routes.

CITATION LIST Patent Literature

PTL 1: Japanese Patent Application Laid-Open No. H10-243708 (1998)

SUMMARY OF INVENTION Technical Problem

Although the travel route generating device of PTL 1 generates theplanned travel route in consideration of the situation in which thefield has a roll-direction inclination relative to the orientation ofthe vehicle body that is traveling in a straight line and performingwork, the travel route generating device of PTL 1 does not give anyparticular consideration on a pitch-direction inclination. In thispoint, the travel route generating device of PTL 1 still has room forimprovement. Specifically, in a case where the field has apitch-direction inclination relative to the vehicle body that istraveling in a straight line, the work vehicle may potentially slidedown by its own weight and depart outside the field while the workvehicle is making a turn on a headland. There has been a demand forreliably preventing such a situation.

Some aspects of the present invention have been made in view of thecircumstances above. An object of some aspects of the present inventionis to provide a route generating system for generating, for a workvehicle, an autonomous travel route including routes being in parallelwith a traveling direction and connection paths each connectingcorresponding ones of the routes, in such a manner as to prevent thework vehicle from departing outside a field due to slide-down at thetime of traveling on the connection path, even in a case where a regionin which the autonomous travel route is generated has a pitch-directioninclination in the traveling direction.

Solution to Problem and Advantageous Effects of Invention

The problem to be solved by the present invention has been describedabove. Next, the following will describe solutions to this problem andeffects achieved by the solutions.

A first aspect of the present invention provides a route generatingsystem including the following features. That is, the route generatingsystem generates a route along which a work vehicle performs autonomoustravel. The route generating system includes a work vehicle settingunit, an altitude information obtaining unit, a traveling directionsetting unit, and a region setting unit. The work vehicle setting unitis configured to obtain vehicle information on the work vehicle. Thealtitude information obtaining unit is configured to obtain altitudeinformation on a specific region where the route is to be generated. Thetraveling direction setting unit is configured to set a travelingdirection of the work vehicle in the specific region. The region settingunit is configured to set, in the specific region, a plurality ofregions including a first region where routes being in parallel with thetraveling direction are generated and second regions where connectionpaths each connecting corresponding ones of the routes are generated.The region setting unit sets widths of the second regions based on thevehicle information, the altitude information, and the travelingdirection, the widths of the second regions extending in parallel withthe traveling direction.

With this, the widths of the second regions are set in consideration ofthe altitude information and the traveling direction. Therefore, forexample, in a case where the second regions have a pitch-directioninclination in the traveling direction, the widths of the second regionscan be achieved in consideration of slide-down of the work vehicle thatmay occur by its own weight at the time of traveling in the secondregion. Consequently, it is possible to prevent the work vehicle fromdeparting outside the specific region.

The route generating system is preferably configured such that theregion setting unit sets the second regions respectively on first andsecond sides of the first region in the traveling direction, and theregion setting unit sets, among the second regions on the first andsecond sides, one of the second regions located on a lower side to havea width larger than a width of the other of the second regions locatedon a higher side, based on the altitude information.

With this, for example, in a case where the specific region is aninclined field with two second regions having a difference of altitude,the width of the one of the headlands on the lower side, on which theweight of the work vehicle is likely to be applied toward the outside ofthe field, can be set wider. Consequently, it is possible to effectivelyprevent the work vehicle from departing outside the field.

The route generating system described above preferably includes thefollowing feature. That is, the work vehicle setting unit sets, as thevehicle information, a turning radius of the work vehicle. The workvehicle setting unit sets, as the turning radius, a turning radiuslarger than a preset reference turning radius based on the altitudeinformation and the traveling direction.

With this, in a case where the second regions have an inclination, aturning radius of the work vehicle at the time of making a turn in thesecond regions can be set larger. This makes it possible to preventslide-down of the work vehicle.

The route generating system described above preferably includes thefollowing feature. That is, the route generating system includes aturning radius designating unit configured to accept, as the turningradius, designation of an arbitrary turning radius. In a case where theturning radius designating unit accepts the designation of the arbitraryturning radius, the work vehicle setting unit sets, as the turningradius of the work vehicle, the arbitrary turning radius according tothe designation.

In this manner, the user can designate the turning radius. Consequently,it is possible to take a countermeasure against the inclined planeindependently of the altitude information on the specific region and theturning characteristics of the work vehicle.

A second aspect of the present invention provides an autonomous travelsystem causing a work vehicle to perform autonomous travel along a routegenerated by the route generating system described above. The autonomoustravel system is configured such that the work vehicle setting unitincludes a vehicle speed setting unit configured to set a first vehiclespeed of the work vehicle in the first region and a second vehicle speedof the work vehicle in the second regions. The autonomous travel systemincludes an autonomous travel control unit configured to controlautonomous travel of the work vehicle. The autonomous travel controlunit controls, based on the altitude information, a vehicle speed of thework vehicle in the second regions to be a third vehicle speed, which islower than the second vehicle speed.

With this, in a case where the second regions have an inclination, avehicle speed of the work vehicle at the time of making a turn on thesecond region can be controlled to be lower than a preset vehicle speed.This makes it possible to prevent slide-down of the work vehicle.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 A side view of an overall configuration of a robot tractor thatis to travel autonomously along a route generated by a route generatingsystem according to one embodiment of the present invention.

FIG. 2 A plan view of the robot tractor.

FIG. 3 A view illustrating a wireless communication terminal that isoperated by a user to perform wireless communication with the robottractor.

FIG. 4 A block diagram illustrating main electrical configurations ofthe robot tractor and the wireless communication terminal.

FIG. 5 A view schematically illustrating an example of an autonomoustravel route, which is a route generated by the route generating system.

FIG. 6 A view illustrating a display example of an entry/selectionscreen on a display of the wireless communication terminal.

FIG. 7 A view illustrating a display example of a work vehicleinformation entry screen on the display of the wireless communicationterminal.

FIG. 8 A view illustrating a display example of a field informationentry screen on the display of the wireless communication terminal.

FIG. 9 A view illustrating a display example of an inclined planecountermeasure setting window on the display of the wirelesscommunication terminal, the inclined plane countermeasure setting windowbeing used to set a countermeasure against slide-down.

FIG. 10 A view illustrating another display example of the inclinedplane countermeasure setting window.

FIG. 11 A view illustrating a display example of a work informationentry screen on the display of the wireless communication terminal.

FIG. 12 A flowchart illustrating a process, performed by the wirelesscommunication terminal, for generating an autonomous travel route byperforming a region setting in consideration of slide-down of atraveling body on a headland.

FIG. 13 A flowchart illustrating a process, performed by an autonomoustravel control unit of the robot tractor, for reducing the slide-down ofthe traveling body on the headland.

FIG. 14 A view schematically illustrating an example of an autonomoustravel route generated by the route generating system in considerationof slide-down of the traveling body on the headland.

DESCRIPTION OF EMBODIMENTS

Next, with reference to the drawings, embodiments of the presentinvention will be described. In each of the drawings, the same referencesigns are given to the same elements, and overlapped description thereofmay be omitted occasionally. Moreover, the designation of the element orthe like corresponding to the same reference sign may be translatedsimply or may be translated into a broader term or a narrower term.

The present invention relates to a route generating system forgenerating a travel route along which a single work vehicle or aplurality of work vehicles is to travel in order that the single workvehicle or the plurality of work vehicles travels in a predeterminedfield to perform farm work entirely or partially within the field. Thepresent invention relates to an autonomous travel system causing a workvehicle to travel along a route generated by the route generatingsystem. In the present embodiment, the description will be given of atractor as one example of the work vehicle. In addition to the tractor,examples of the work vehicle include a riding-type working machine suchas a rice transplanter, a combine harvester, a civil engineering andconstruction work machine, and a snowplow, as well as a walking-typework machine. In Description herein, autonomous travel means that atractor is caused to travel along a predetermined route by controlling,by a control unit (electrical control unit: ECU) of the tractor, aconfiguration of the tractor associated with traveling. Autonomous workmeans that a tractor is caused to perform work along a predeterminedroute by controlling, by the control unit of the tractor, aconfiguration of the tractor associated with work. In contrast to this,manual travel and manual work mean that travel and work are performed byuser's operation of each of the configuration of the tractor.

In the following description, a tractor that is to perform theautonomous travel and the autonomous work is referred to as an “unmannedtractor” or a “robot tractor” occasionally, whereas a tractor that is toperform the manual travel and the manual work is referred to as a“manned tractor” occasionally. In the field, when a part of farm work isperformed by the unmanned tractor, the rest of the farm work isperformed by the manned tractor. Farm work in a single field performedby the unmanned tractor and the manned tractor is referred to ascooperative farm work, track farm work, following farm work, or the likeoccasionally. The unmanned tractor and the manned tractor herein differfrom each other in presence of user's operation, and are basicallycommon in each element. That is, the user can ride on (get on) andoperate the unmanned tractor (i.e., the user can use the tractor as themanned tractor). Meanwhile, the user can get off the manned tractor andcause the tractor to perform the autonomous travel and the autonomouswork (i.e., the user can use the tractor as the unmanned tractor). Thecooperative farm work may include not only “performing farm work withina single field by an unmanned vehicle and a manned vehicle” but also“performing farm work in different fields, such as adjacent fields, byan unmanned vehicle and a manned vehicle at the same time.”

Next, with reference to the drawings, embodiments of the presentinvention will be described. FIG. 1 is a side view of an overallconfiguration of a robot tractor 1 that is to travel autonomously alonga route generated by a route generating system 99 according to oneembodiment of the present invention. FIG. 2 is a plan view of the robottractor 1. FIG. 3 illustrates a wireless communication terminal 46 thatis operated by a user to perform wireless communication with the robottractor 1. FIG. 4 is a block diagram illustrating main electricalconfigurations of the robot tractor 1 and the wireless communicationterminal 46.

The route generating system 99 according to the one embodiment of thepresent invention is configured to generate an autonomous travel route(route) P along which the robot tractor 1 shown in FIG. 1 is to travelfor autonomous travel and autonomous work (see FIG. 5). In the presentembodiment, the main features of the route generating system 99 areincluded in the wireless communication terminal 46 communicable with therobot tractor 1.

An autonomous travel system 100 according to one embodiment of thepresent invention is configured to cause the robot tractor 1 to travelautonomously along an autonomous travel route P generated by the routegenerating system 99.

First, description will be given of the robot tractor (hereinafter,simply referred to as a “tractor” occasionally) 1 with reference toFIGS. 1 and 2.

The tractor 1 includes a traveling body 2 serving as a vehicle body thatcan perform autonomous travel within a field region (specific region).To the traveling body 2, a work machine can be attached. The workmachine may be selected from various types of work machines such astillers (cultivators), plows, fertilizers, mowers, and seeders. In thepresent embodiment, a work machine 3 that is a rotary tiller is attachedto the traveling body 2.

With reference to FIGS. 1 and 2, the following describes further detailsof the configuration of the tractor 1. As illustrated in FIG. 1, thetraveling body 2 of the tractor 1 includes a front part supported bypaired right and left front wheels 7, and a rear part supported bypaired right and left rear wheels 8.

The traveling body 2 has an engine hood 9 disposed in the front partthereof. In the present embodiment, stored within the engine hood 9 arean engine 10 as a drive source of the tractor 1, a fuel tank (notshown), and the like. The engine 10 may be a diesel engine, for example.However, this is not limitative. For instance, the engine 10 may be agasoline engine. Instead of or in addition to the engine 10 as the drivesource, an electric motor may be used. The fuel tank may alternativelybe disposed outside the engine hood 9.

A cabin 11 where the user rides is disposed behind the engine hood 9.The cabin 11 mainly includes, inside thereof, a steering handle 12 to besteered by the user, a seat 13 where the user is able to sit, andvarious operating devices for performing various types of operation.

However, the work vehicle with the cabin 11 is not limitative.Alternatively, the work vehicle without the cabin 11 may be used.

Examples of the operating devices include a monitor 14, a throttle lever15, a main shift lever 27, a plurality of hydraulic control levers 16, apower take-off (PTO) switch 17, a PTO shift lever 18, a sub-shift lever19, and a work machine lifting switch 28, which are illustrated in FIG.2. These operating devices are disposed adjacent to the seat 13 or thesteering handle 12.

The monitor 14 is capable of displaying various kinds of informationabout the tractor 1. The throttle lever 15 is an operation tool forsetting an output speed of the engine 10. The main shift lever 27 is anoperation tool for steplessly changing a traveling speed of the tractor1. The hydraulic control lever 16 is an operation tool for switching anexternal hydraulic takeoff valve (not shown). The PTO switch 17 is anoperation tool for switching transmission/break of power to anunillustrated PTO shaft (power transmission shaft) that protrudes fromthe rear end of a transmission 22. Specifically, if the PTO switch 17 isin an ON-state, power is transmitted to the PTO shaft, thereby causingthe PTO shaft to rotate. Meanwhile, if the PTO switch 17 is in anOFF-state, power to the PTO shaft breaks, thereby causing the PTO shaftto stop rotating. The PTO shift lever 18 is an operation tool forshifting a rotation speed of the PTO shaft. The sub-shift lever 19 is anoperation tool for switching a gear ratio of a sub-traveling speed shiftgear mechanism in the transmission 22. The work machine lifting switch28 is an operation tool for up-down operation in level of the workmachine 3 attached to the traveling body 2 within a predetermined range.

As illustrated in FIG. 1, the tractor 1 includes a chassis 20 providedat a lower part of the traveling body 2. The chassis 20 is constitutedby a body frame 21, the transmission 22, a front axle 23, and a rearaxle 24, for example.

The body frame 21 is a support member at the front part of the tractor1, and supports the engine 10 directly or via a vibro-isolatingmaterial, for example. The transmission 22 is configured to change powerfrom the engine 10 and transmit the power to the front axle 23 and therear axle 24. The front axle 23 is configured to transmit the power fromthe transmission 22 to the front wheels 7. The rear axle 24 isconfigured to transmit the power from the transmission 22 to the rearwheels 8.

As illustrated in FIG. 4, the tractor 1 includes a control unit(autonomous travel control unit) 4 that controls movement (e.g., forwardmovement, rearward movement, stop, and turn) of the traveling body 2 andmovement (e.g., lift, drive, and stop) of the work machine 3. Thecontrol unit 4 includes a CPU, a ROM, a RAM, and an I/O (each notshown), for example. The CPU can read various programs and/or the likefrom the ROM and execute the programs and/or the like. The control unit4 is electrically connected to controllers and a wireless communicationunit 40, for example. The controllers control elements (e.g., the engine10) of the tractor 1. The wireless communication unit 40 enableswireless communication with another wireless communication unit.

The tractor 1 includes, as the above controllers, at least an enginecontroller, a vehicle speed controller, a steering controller, and alifting controller (each not shown). Each of the controllers can controla corresponding one of the elements of the tractor 1 according to anelectric signal from the control unit 4.

The engine controller controls the speed of the engine 10, for example.Specifically, the engine 10 includes a speed governor 41 with anactuator (not shown), which is configured to change the speed of theengine 10. The engine controller controls the speed governor 41, therebycontrolling the speed of the engine 10. The engine 10 further includes afuel injection device that controls a timing and an amount of fuelinjected (supplied) into a combustion chamber of the engine 10. Theengine controller controls the fuel injection device to stop fuel supplyto the engine 10, thereby stopping driving of the engine 10.

The vehicle speed controller controls the vehicle speed of the tractor1. Specifically, the transmission 22 includes a gear shifter 42 such asa hydraulic continuously variable transmission of movable swash platetype. The vehicle speed controller causes an actuator (not shown) tochange an angle of a swash plate of the gear shifter 42, therebychanging a gear ratio of the transmission 22 to obtain a desired vehiclespeed.

The steering controller controls a rotational angle of the steeringhandle 12. Specifically, a steering actuator 43 is disposed halfway arotary shaft (steering shaft) of the steering handle 12. In order tocause the tractor 1 to travel on a predetermined route under such aconfiguration, the control unit 4 calculates a suitable rotational angleof the steering handle 12 so as to cause the tractor 1 to travel alongthe route. The control unit 4 outputs a control signal to the steeringcontroller so that the rotational angle of the steering handle 12matches the calculated rotational angle. The steering controller drivesthe steering actuator 43 according to the control signal from thecontrol unit 4 to control the rotational angle of the steering handle12. Alternatively, the steering controller may control a steering angleof the front wheels 7 of the tractor 1, rather than the rotational angleof the steering handle 12. In such a configuration, the steering handle12 would not be rotated even when the tractor 1 makes a turn.

The lifting controller controls up and down movement of the work machine3. Specifically, the tractor 1 includes a lifting actuator 44constituted by, e.g., a hydraulic cylinder. The lifting actuator 44 isdisposed adjacent to a three-point link mechanism that connects the workmachine 3 to the traveling body 2. The lifting controller drives thelifting actuator 44 according to a control signal from the control unit4 under such a configuration, so as to cause the work machine 3 to moveupwardly and downwardly appropriately. This allows support of the workmachine 3 at a desired level, such as a retracting level (a level whereno farm work is performed) and a work level (a level where farm work isperformed), so as to cause the work machine 3 to perform farm work.

The above-described unillustrated controllers control theircorresponding elements, such as the engine 10, according to the signalsfrom the control unit 4. From this, it can be understood that thecontrol unit 4 substantially controls the elements.

The tractor 1 provided with the above-described control unit 4 isconfigured to allow the user riding in the cabin 11 to execute varioustypes of operation to cause the control unit 4 to control the components(the traveling body 2, the work machine 3, and/or the like) of thetractor 1 so that the tractor 1 can perform farm work while travelingwithin the field. In addition, the tractor 1 of the present embodimentis capable of performing autonomous travel and autonomous work accordingto various control signals outputted from the wireless communicationterminal 46 even when the operator does not ride on the tractor 1.

Specifically, as illustrated in, e.g., FIG. 4, the tractor 1 includesvarious components that enable autonomous travel and autonomous work.For instance, the tractor 1 includes, e.g., a position measuring antenna6 required to obtain position information on itself (traveling body 2)from a position measuring system. With such a configuration, the tractor1 is capable of obtaining the position information on itself from theposition measuring system to travel autonomously in the field (specificregion).

Next, with reference to, e.g., FIG. 4, the following describes detailsof the configuration of the tractor 1 that enables the autonomoustravel. Specifically, the tractor 1 of the present embodiment includesthe position measuring antenna 6, a wireless communication antenna 48,various sensors, and a memory unit 55, for example. In addition, thetractor 1 of the present embodiment includes an inertial measurementunit 53 and an inclination threshold determination unit 50 as aconfiguration that suppresses or reduces slip-down of the traveling body2 on an inclined plane to enable safe autonomous travel.

The position measuring antenna 6 receives a signal from a positioningsatellite included in the position measuring system such as a globalnavigation satellite system (GNSS). As illustrated in FIG. 1, theposition measuring antenna 6 is disposed on the top face of a roof 5provided on the cabin 11 of the tractor 1. A position measuring signalreceived by the position measuring antenna 6 is inputted to a positioninformation calculating unit 49 illustrated in FIG. 4. The positioninformation calculating unit 49 calculates the position information onthe traveling body 2 (to be exact, the position measuring antenna 6) ofthe tractor 1 as latitude/longitude information, for example. Theposition information obtained by the position information calculatingunit 49 is stored in the memory unit 55. The position information isread by the control unit 4 at an appropriate timing, and the positioninformation is used for autonomous travel.

Although the present embodiment adopts a high-accuracy global navigationsatellite system using a global navigation satellite system real-timekinematic (GNSS-RTK), this is not limitative. Other position measuringsystems may be adoptable as long as a position coordinate can beobtained with a high accuracy. For instance, a differential globalpositioning system (DGPS) or a satellite-based augmentation system(SBAS) is available.

The wireless communication antenna 48 receives a signal from thewireless communication terminal 46 operated by the user, and transmits asignal to the wireless communication terminal 46. As illustrated in FIG.1, the wireless communication antenna 48 is disposed on the top face ofthe roof 5 provided on the cabin 11 of the tractor 1. A signal outputtedfrom the wireless communication terminal 46 and received by the wirelesscommunication antenna 48 is subjected to signal processing in a wirelesscommunication unit 40 shown in FIG. 4, and then is inputted to thecontrol unit 4. A signal from the control unit 4 and/or the like to thewireless communication terminal 46 is subjected to signal processing bythe wireless communication unit 40, and then is transmitted from thewireless communication antenna 48, so that the signal is received by thewireless communication terminal 46.

The inertial measurement unit 53 is capable of identifying a posture (aroll angle, a pitch angle, and a yaw angle) of the traveling body 2.Based on the information on the posture of the traveling body 2 measuredby the inertial measurement unit 53, it is possible to work out aninclination of the field.

The inclination threshold determination unit 50 obtains the currentinclination degree (the degree of the inclination determined based on aroll angle and a pitch angle) of the traveling body 2 from the detectionresult of the inertial measurement unit 53, and determines whether ornot the current inclination degree exceeds a first threshold. As will bedescribed in detail later, the control unit 4 controls the vehicle speedof the traveling body 2 at the time of making a turn, based on thedetection result of the inclination threshold determination unit 50.

Stored in the memory unit 55 is a travel route (path) P where thetractor 1 performs autonomous travel. The travel route P is made byalternately connecting autonomous work paths (routes where farm work isperformed) each being in a linear or a polygonal line shape and arcuateconnection paths (turning paths) P2 used for turn. In addition, in thememory unit 55, position information (travel trajectory) on the tractor1 that is performing autonomous travel and information on the posture ofthe traveling body 2 associated with the position information arestored. In addition to them, various types of information required tocause the tractor 1 to perform autonomous travel and autonomous work arestored in the memory unit 55.

As illustrated in FIG. 3, the wireless communication terminal 46 of thepresent embodiment is provided as a tablet personal computer. Forexample, the user outside the tractor 1 can view and check theinformation (e.g., information from various sensors attached to therobot tractor 1) displayed on the display 37 of the wirelesscommunication terminal 46. In addition, the user can operate hardwarekeys 38 arranged adjacent to the display 37, a touch panel 39 arrangedto cover the display 37, and/or the like to transmit a control signalfor controlling the tractor 1 to the control unit 4 of the tractor 1.Examples of the control signals outputted from the wirelesscommunication terminal 46 to the control unit 4 include signalsregarding the route for autonomous travel and autonomous work, andsignals for start, stop, termination, emergent stop, temporary stop, andrestart after the temporary stop. However, this is not imitative.

The wireless communication terminal 46 is not limited to the tabletpersonal computer. Instead of this, the wireless communication terminal46 may be a laptop personal computer. Alternatively, in a case where therobot tractor 1 and a manned tractor perform cooperative work, themonitor 14 mounted on the manned tractor may be a wireless communicationterminal.

The tractor 1 configured as above is capable of performing farm workwith the work machine 3 while traveling autonomously along a route inthe field according to the operator's instruction given with thewireless communication terminal 46.

Specifically, the user can perform various settings with the wirelesscommunication terminal 46 to generate an autonomous travel route P thatis a series of routes made by alternately connecting autonomous workpaths (liner routes where autonomous work is performed) P1 each being ina linear or a polygonal line shape and arcuate connection paths (turningpaths where the tractor 1 makes a turn and/or performs switch back) P2each connecting corresponding ones of the ends of the work routes P1.

FIG. 5 illustrates an example of the autonomous travel route P. Theautonomous travel route P is generated so as to connect a work startposition S and a work end position E, each of which is designated inadvance. FIG. 5 is a view schematically illustrating an example of theautonomous travel route P generated by the route generating system 99.As illustrated in FIG. 5, the autonomous travel route P is generatedsuch that headlands (second regions) and unplowed regions (sidemargins), which are non-work regions where the work machine 3 does notperform work, are set in the field (specific region) and a regionobtained by subtracting the non-work regions from the field is set as awork region (first region). The autonomous work paths (routes) P1 aregenerated so as to be arranged side by side in the work region (firstregion), whereas the connection paths P2 are generated so as to bearranged in the headlands (second regions), which are the non-workregions. In the present embodiment, a region obtained by combining thenon-work regions with the work region is referred to as the “specificregion”.

By inputting (transmitting), to the control unit 4, the information onthe above autonomous travel route P and performing a predeterminedoperation, the user can allow the control unit 4 to control the tractor1 such that the tractor 1 travels autonomously along the autonomoustravel route P and the work machine 3 performs farm work along theautonomous work paths P1.

With mainly reference to FIG. 4, the following describes further detailsof the wireless communication terminal 46, which includes mainconstituent elements of the route generating system 99 according to theone embodiment of the present invention.

As illustrated in FIGS. 3 and 4, the wireless communication terminal 46of the present embodiment includes the display 37, the hardware keys 38,and the touch panel 39, as well as main elements such as a displaycontrol unit 31, a memory unit 32, a route generating unit 35, a workvehicle setting unit 36, a field information setting unit 45, a workinformation setting unit 47, the inclination threshold determinationunit 54, and a turning radius designating unit 59, for example.

The display control unit 31 generates display data that is displayed onthe display 37, and controls the display screen to be switched from oneto another appropriately. The display control unit 31 can generate anentry/selection screen 60 as an initial screen (menu screen) as shown inFIG. 6, and can display the entry/selection screen 60 on the display 37.In response to a predetermined operation performed on theentry/selection screen 60, the display control unit 31 can generateentry screens 70, 80, and 90 (described later), and can switch thedisplay screen of the display 37 between the entry screens 70, 80, and90.

The route generating unit 35 generates a route that is to be inputted(transmitted) to the tractor 1. The route generating unit 35 of thepresent embodiment generates the autonomous travel route P along whichthe tractor 1 is caused to travel autonomously. In a case where workvehicle information, field information, and work information (each willbe described below) are entered and a predetermined operation isperformed, the route generating unit 35 automatically generates theautonomous travel route P. The route generating unit 35 generates(calculates) the autonomous travel route P in consideration ofslide-down of the tractor 1 (traveling body 2) that may occur by its ownweight, if necessary. The autonomous travel route P thus generated isstored in the memory unit 32.

The work vehicle setting unit 36 accepts the work vehicle information(the information on the traveling body 2 and the work machine 3) enteredon the work vehicle information entry screen 70, which will be describedlater. The work vehicle information set by the work vehicle setting unit36 is stored in the memory unit 32.

The field information setting unit 45 accepts the field information (theinformation on the field) and/or the like entered on the fieldinformation entry screen 80, which will be described later. The fieldinformation set by the field information setting unit 45 is stored inthe memory unit 32.

Specifically, the field information setting unit 45 of the presentembodiment includes a field shape obtaining unit 52, an altitudeinformation obtaining unit 56, a traveling direction setting unit 57,and a region setting unit 58.

The field shape obtaining unit 52 obtains the (planar) shape of thefield, e.g., by causing the tractor 1 to travel along the outerperiphery of the field to go around the field once and recordingtransitions of the position of the position measuring antenna 6 duringthe traveling. The shape of the field obtained by the field shapeobtaining unit 52 is stored in the memory unit 32. However, the way ofobtaining the shape of the field is not limitative. Alternatively, forexample, the shape of the field may be obtained as a polygon identifiedbased on a so-called cycle graph in which line segments connecting thepoints corresponding to the recorded position information on the cornersof the field do not intersect one another.

The altitude information obtaining unit 56 obtains, e.g., by loading mapdata, altitude information on various points in the field having beenregistered by the field shape obtaining unit 52.

The traveling direction setting unit 57 obtains a traveling direction ofthe tractor 1 designated by the user.

The region setting unit 58 sets, in the field (specific region), thework region (first region) and the headlands (second regions) based onthe work vehicle information (specifically, information on the turningradius) set by the work vehicle setting unit 36, the altitudeinformation on the various points of the field obtained by the altitudeinformation obtaining unit 56, and the traveling direction (workdirection) set by the traveling direction setting unit 57. The regionsetting unit 58 sets the headlands (second regions) respectively onfirst and second sides of the work region (first region) in thetraveling direction. The region setting unit 58 sets the headlands(second regions) in consideration of the sizes of the headlands requiredfor the tractor 1 to make a turn with the preset turning radius. As willbe described in detail later, in consideration of slide-down of thetraveling body 2 that may occur due to the inclination of the field, theregion setting unit 58 of the present embodiment can set at least one ofthe lengths of the headlands (hereinafter, simply referred to as“headland widths” occasionally) wider than a normally used value in adirection in parallel with the traveling direction.

The work information setting unit 47 accepts the work information (theinformation on the work mode and/or the like) entered on the workinformation entry screen 90, which will be described later. The workinformation set by the work information setting unit 47 is stored in thememory unit 32.

The inclination threshold determination unit 54 can determine whether ornot the inclination degrees of the headlands exceed a second thresholdand a third threshold based on the altitude information obtained by thealtitude information obtaining unit 56. As will be described in detaillater, the region setting unit 58 appropriately sets the length of thework region (first region) and the headland widths in the direction inparallel with the traveling direction, based on the determination resultof the inclination threshold determination unit 54. In addition, theroute generating unit 35 appropriately sets the autonomous travel routeP based on the determination result of the inclination thresholddetermination unit 54.

The turning radius designating unit 59 accepts user's instruction on theturning radius in a case where the inclination threshold determinationunit 54 determines that at least one of the inclination degrees of theheadlands exceeds the third threshold. The turning radius designatingunit 59 of the present embodiment can set, as the turning radius, avalue larger than a reference turning radius (minimum turning radius)specific to the model of the tractor 1. Alternatively, the value may besmaller than the reference turning radius. The turning radius set by theturning radius designating unit 59 takes priority over the turningradius accepted by the work vehicle setting unit 36.

The memory unit 32 includes an involatile memory (for example, a flashROM). The memory unit 32 can store therein the work vehicle informationset by the work vehicle setting unit 36, the field information set bythe field information setting unit 45, the work information set by thework information setting unit 47, and the information on the turningradius set by the turning radius designating unit 59, for example. Thememory unit 32 can further store therein the information on theautonomous travel route P generated by the route generating unit 35, forexample.

With mainly reference to FIGS. 6 to 11, which illustrate screens to bedisplayed on the display 37 of the wireless communication terminal 46,the following describes in detail how the user operates the wirelesscommunication terminal 46 to set the work vehicle information, the fieldinformation, the work information, and/or the like to generate theautonomous travel route P. FIG. 6 is a view illustrating a displayexample of the entry/selection screen 60 on the display 37 of thewireless communication terminal 46. FIG. 7 is a view illustrating adisplay example of the work vehicle information entry screen 70 on thedisplay 37 of the wireless communication terminal 46. FIG. 8 is a viewillustrating a display example of the field information entry screen 80on the display 37 of the wireless communication terminal 46. FIG. 9 is aview illustrating a display example of the inclined plane countermeasuresetting window 82 on the display 37 of the wireless communicationterminal 46, the inclined plane countermeasure setting window 82 beingused to set a countermeasure against slide-down. FIG. 10 is a viewillustrating another display example of the inclined planecountermeasure setting window 82. FIG. 11 is a view illustrating adisplay example of the work information entry screen 90 on the display37 of the wireless communication terminal 46.

In a step before the user starts the setting on the work vehicleinformation, the field information, and the work information, thedisplay 37 of the wireless communication terminal 46 displays, as aninitial screen (menu screen), the entry/selection screen 60 generated bythe display control unit 31, as shown in FIG. 6. The entry/selectionscreen 60 mainly displays a work vehicle information entry operationsection 61, a field information entry operation section 62, a workinformation entry operation section 63, a travel routegeneration/transfer operation section 64, and a farm work startoperation section 65.

These operation sections are provided as virtual buttons (so-calledicons) displayed on the display 37. All “buttons” in the followingdescription refer to virtual buttons displayed on the display 37. Theuser may operate a desired one of these buttons by touching, withhis/her finger or the like, a portion of the touch panel 39corresponding to the region where the desired button is displayed.

First, the user operates the work vehicle information entry operationsection 61 on the entry/selection screen 60 in order to enter workvehicle information. Consequently, the display screen is switched to thework vehicle information entry screen 70 illustrated in FIG. 7.

On the work vehicle information entry screen 70, it is possible to enterwork vehicle information on the traveling body 2 and the work machine 3attached to the traveling body 2. Specifically, the work vehicleinformation entry screen 70 includes the boxes for entering various workvehicle information. Examples of the work vehicle information encompassthe model of the tractor 1, the position where the position measuringantenna 6 is attached to the traveling body 2, the lateral width of thetractor 1, the lateral width (work width) of the work machine 3, adistance from the rear edge of the three-point link mechanism (the rearend of the lower link) to the rear end of the work machine 3, a vehiclespeed during work, a vehicle speed on the headland (at the time ofturning), an engine speed during work, an engine speed on the headland(at the time of turning), and a turning radius.

In the present embodiment, when the model of the tractor 1 is entered,the preset values of the lateral width, the turning radius (minimumturning radius), and the like, which are preliminarily stored inassociation with the model, are automatically entered into the boxes.However, the user may set a value different from the preset value, e.g.,by operating a pull-down menu in each box and/or directly entering anumerical value into each box.

When all of the items on the work vehicle information entry screen 70are entered and the user operates a “confirm vehicle setting” button(not shown) thereon, the work vehicle information is accepted by thework vehicle setting unit 36, and is stored in the memory unit 32, sothat the setting of the work vehicle information is completed.

Specifically, settings on the information on the vehicle speed duringwork (first vehicle speed) and the information on the vehicle speed onthe headland (second vehicle speed) among the work vehicle informationare accepted by a vehicle speed setting unit (not shown) of the workvehicle setting unit 36.

When the user operates the field information entry operation section 62on the entry/selection screen 60 shown in FIG. 6 appearing again afterthe user has ended the setting on the work vehicle information, thedisplay screen of the display 37 is switched to the field informationentry section 80 shown in FIG. 8.

On the field information entry screen 80, it is possible to enterinformation on a specific region (field) where the traveling body 2travels. Specifically, the field information entry screen 80 includes aplane surface display section 81, which displays the shape of the fieldby graphics (graphically). The field information entry screen 80includes a box “field outer periphery position and shape” with “recordstart” and “reset” buttons. The field information entry screen 80further includes boxes “work start position”, “work end position”, and“work direction” each with “set” and “reset” buttons. The fieldinformation entry screen 80 also includes a box “altitude information”with a “read” button.

If the “record start” button for the “field outer periphery position andshape” is operated, the wireless communication terminal 46 is switchedto a field shape record mode. In the field shape record mode, when thetractor 1 travels along the outer periphery of the field to go aroundthe field once, for example, the field shape obtaining unit 52 recordstransitions of the position of the position measuring antenna 6 duringthe traveling. Thus, the field shape obtaining unit 52 obtains(calculates) the shape of the field. In this manner, it is possible todesignate the position and shape of the field. The position and shape ofthe outer periphery of the field calculated (designated) in this mannerare graphically displayed on the plane surface display section 81. Byoperating the “reset” button, it is possible to record (designate) theposition of the outer periphery of the field again.

If the “set” button for the “work start position” is operated, the shapeof the field obtained in the above-described manner is displayed on theplane surface display section 81 of the field information entry screen80 so as to overlap map data. In this state, the user may select anypoint near the contour of the field, so that the position informationnear the selected point can be set as the work start position. The “workend position” can be set in a similar manner to the “work startposition”.

If the “set” button for the “work direction” is operated, the shape ofthe field, the work start position, and the work end position obtainedin the above-described manner are displayed on the plane surface displaysection 81 of the field information entry screen 80 so as to overlap mapdata. In this state, the user may select any two points on the contourof the direction. The work direction (traveling direction) thus set isaccepted by the traveling direction setting unit 57.

If the “read” button for the “altitude information” is operated, awindow for designating a file (not shown) is displayed. In this state,by attaching to the wireless communication terminal an external memoryin which a file describing altitude distribution data is stored anddesignating this file, the altitude information obtaining unit 56 canobtain the altitude information. The content of the altitudedistribution data can be numerical data indicative of the elevationobtained by, e.g., airborne laser scanning performed with a mesh unit ofseveral meters. However, this is not limitative. Alternatively, forexample, the altitude distribution data may be data indicative of thepositions and shapes of contour lines on the map. The information on thealtitude distribution is obtained by the altitude information obtainingunit 56, and the altitude information obtaining unit 56 can perform acalculation to obtain the inclinations at various points in the field.

When the settings on all the items on the field information entry screen80 are completed, the inclination threshold determination unit 54determines whether or not the inclination degree of the field (headland)exceeds the second threshold. Unless otherwise stated, the inclinationdegree of the field (headland) in the following description refers to apitch-component inclination in the work direction (traveling direction).If the inclination threshold determination unit 54 determines that atleast one of the inclination degrees of the headlands exceeds the secondthreshold, an inclined plane countermeasure setting window 82 isdisplayed so as to overlap the field information entry screen 80, asillustrated in FIG. 9. More specifically, in a case where a headland isinclined lower toward the outer side of the field, there is apossibility that the traveling body 2 may slide down by a centrifugalforce and its own weight while making a turn on the headland andaccordingly depart outside the field. In order to prevent thissituation, the inclined plane countermeasure setting window 82 proposingthe user to perform a region setting for increasing the headland widthis displayed.

For example, the inclined plane countermeasure setting window 82displays a countermeasure for reducing slip-down together with thefollowing message: “Pitch-direction inclination in work direction hasbeen detected. Please select countermeasure against slip-down at thetime of turning on headland.” Specifically, the inclined planecountermeasure setting window 82 of the present embodiment displays acountermeasure “increase headland width” with a check box on the leftside thereof. Via the check box, the user can give an instruction toconduct this countermeasure. If the user puts a check mark in this checkbox, an input box displayed on the right side becomes possible to acceptan entry of a headland width. At the time when the inclined planecountermeasure setting window 82 is displayed, a value is preset in thebox for entering the headland width. This preset value is obtained by acalculation appropriately performed based on the turning radius set bythe work vehicle setting unit 36, the altitude information (inclinationdegree) obtained by the altitude information obtaining unit 56, and thetraveling direction obtained by the traveling direction setting unit 57in order to effectively prevent slide-down. However, the user can set avalue different from the preset value, by performing a touch operationon this box with his/her finger or the like.

If the inclination threshold determination unit 54 determines that atleast one of the inclination degree of the headlands exceeds not onlythe second threshold but also the third threshold, the inclined planecountermeasure setting window 82 displays the countermeasure “increaseheadland width” as well as a countermeasure “change turning radius”, asillustrated in FIG. 10. Also for this countermeasure, a check box isprovided. If the user puts a check mark in this check box, an input boxdisplayed on the right side becomes possible to accept an entry of anarbitrary turning radius. At the time when the inclined planecountermeasure setting window 82 is displayed, a value is preset in thebox for entering the turning radius. This preset value is obtained by acalculation appropriately performed based on the altitude information(inclination degree) obtained by the altitude information obtaining unit56 and the traveling direction obtained by the traveling directionsetting unit 57 in order to effectively prevent slide-down.Alternatively, the user can set a value different from the preset value,by performing a touch operation on this box with his/her finger or thelike. The information on the turning radius designated in this box isaccepted by the turning radius designating unit 59.

In the present embodiment, the countermeasures for preventing theslide-down of the traveling body 2 can be selected alone or incombination. The user may put check marks in the desired check boxes asillustrated in FIG. 10, for example. After that, the user may operate a“register” button in a lower portion of the inclined planecountermeasure setting window 82.

In response to the operation of the “register” button, the regionsetting unit 58 sets the work region (first region) and the headlands(second regions) in the field (specific region) so as to achieve theheadland width designated on the inclined plane countermeasure settingwindow 82 and/or the turning radius accepted by the turning radiusdesignating unit 59. Specifically, for example, in order that the workregion and the headlands are not extended outside the field, theheadland width designated on the inclined plane countermeasure settingwindow 82 is achieved by increasing the headland width, rather than byreducing the length of the work region in the traveling direction asneeded.

In a case where the headlands on the first and second sides of the fieldin the traveling direction have a difference of altitude, the regionsetting unit 58 of the present embodiment sets (increases) the width L2of the headland determined to be on the lower side (down-side) such thatthe width L2 matches the headland width having been set on the inclinedplane countermeasure setting window 82, whereas the region setting unit58 sets the width L1 of the headland on the higher side (up-side) to bea headland width smaller than the value set for the lower side (e.g., aminimum width determined based on the turning radius) (L1<L2).

When the user operates the work information entry operation section 63on the entry/selection screen 60 shown in FIG. 6 appearing again afterthe user has ended the setting on the field information and the settingon the countermeasure against the inclined plane if needed, the displayscreen is switched to the work information entry screen 90 illustratedin FIG. 11.

A box “work content” on the work information entry screen 90 allowsselection of work to be performed, among tilling work, ground levelingwork, fertilizing work, seeding work, chemical agent application work,herbicide application work, and the like. By operating a pull-down menuin this box, the user can set desired autonomous work to be performed bythe tractor 1.

A box “with/without cooperative work of multiple vehicles” on the workinformation entry screen 90 allows selection of whether to perform workby multiple tractors (e.g., two vehicles including the robot tractor 1and a manned tractor) in a single field (i.e., whether to performcooperative work). By operating a pull-down menu in this box, the usercan set “with cooperative work” or “without cooperative work”. Note thatthe box “with/without cooperative work of multiple vehicles” may beomitted.

A box “cooperative work mode” on the work information entry screen 90becomes available only when “with cooperative work” is set in the box“with/without cooperative work of multiple vehicles”. The box“cooperative work mode” allows selection of which type of work toperform, among cooperative work (track cooperative work) in whichmultiple tractors travel on respective different autonomous work pathsP1, cooperative work (following cooperative work) in which multipletractors travel on the same autonomous work path P1, and the like. Byoperating a pull-down menu in this box, the user can set a desired oneof the cooperative work modes.

A box “overlap width” on the work information entry screen 90 allowssetting on a width (overlap amount) allowing overlap of the widths ofadjacent ones of the autonomous work paths P1 where the work machine 3travels. By operating a pull-down menu in this box or directly enteringa numerical value, the user can set the overlap amount.

A box “skip number” on the work information entry screen 90 allowsselection of the number of autonomous work paths to be interposedbetween an arbitrary autonomous work path P1 in the autonomous travelroute P, along which the tractor 1 is to travel, and another autonomouswork path P1 along which the tractor 1 is to travel subsequently to thearbitrary autonomous work path P1 (the number of rows of paths to beskipped during work). In the present embodiment, by operating apull-down menu in this box, the user can set the skip number.

A box “unplowed region width” on the work information entry screen 90allows setting on the widths of the non-work regions (i.e., unplowedregions, which may also be called as side margins) located on two endsof the travel region in a direction along which the autonomous workpaths P1 for the tractor 1 are arranged side by side. In this box, arecommended width is set preliminarily. However, by operating apull-down menu in this box, the user can set, as the unplowed regionwidth, a value that is an integral multiple of the work width, forexample. However, this is not limitative. Alternatively, the user maydirectly enter a desired numerical value for the unplowed region width.

When the user enters information in all or some of the boxes on the workinformation entry screen 90 as needed and operates a “confirm” button(not shown), the work information is accepted by the work informationsetting unit 47, and the entry/selection screen 60 illustrated in FIG. 6is displayed again. When the user selects the travel routegeneration/transfer operation section 64 in this state, an autonomoustravel route P for the tractor 1 is automatically generated, and theautonomous travel route P thus generated is stored in the memory unit32. In a case where the user has selected the countermeasure(s) forpreventing slid-down on the inclined plane, the autonomous travel routeP is generated in consideration of the countermeasure(s). Specifically,generated in this case is the autonomous travel route P including theconnection paths P2 with which the turning radius designated by theturning radius designating unit 59 can be achieved.

When the autonomous travel route P is generated, a “path simulation”button is displayed on the display screen of the display 37 in aselectable manner. When the “path simulation” button is operated, animage expressing the generated autonomous travel route P with, e.g.,arrows and lines is displayed. Instead of the image, an animation of atractor moving along the autonomous travel route P may be displayed.

In addition, a “transfer data” button and a “return to entry/selectionscreen” button are displayed on the display screen of the display 37 ina selectable manner. Selecting the “transfer data” button can give aninstruction to transmit the information on the autonomous travel route Pto the tractor 1. Selecting the “return to entry/selection screen”button switches the display screen to the entry/selection screen 60.

As described above, with the route generating system 99 of the presentembodiment, the information on the autonomous travel route P generatedby the wireless communication terminal 46 can be transmitted to thecontrol unit 4 of the tractor 1. The control unit 4 stores, in thememory unit 55 electrically connected to the control unit 4, theinformation on the autonomous travel route P received from the wirelesscommunication terminal 46.

After the information on the autonomous travel route P generated by thewireless communication terminal 46 is transmitted to the tractor 1, theuser may steer the tractor 1 to bring the tractor 1 to the work startposition S and operate the farm work start operation section 65 on theentry/selection screen 60. Consequently, the tractor 1 starts autonomoustravel along the autonomous travel route P. While the tractor 1 isperforming autonomous travel, the display 37 of the wirelesscommunication terminal 46 displays a monitoring screen including animage transmitted from a camera (not shown) of the traveling body 2. Theuser views the monitoring screen and transmits a control signal to thetractor 1 as needed. In this manner, the user continuously monitors thetractor 1 that is performing autonomous travel.

Next, with reference to the flowchart in FIG. 12, the followingdescribes details of a process, performed by the wireless communicationterminal 46, for achieving a region setting in consideration ofslide-down of the traveling body 2 on the headland and generating asuitable autonomous travel route P in a case where the field (specificregion) has an inclination component (a difference of altitude) that isequal to or greater than a certain level when viewed in the travelingdirection. FIG. 12 is a flowchart illustrating a process, performed bythe wireless communication terminal 46, for generating an autonomoustravel route P adapted to an inclined plane, by performing the regionsetting in consideration of the slide-down of the traveling body 2 onthe headland.

First, in step S101, the inclination threshold determination unit 54determines whether or not the inclination degree of the field (headland)exceeds the second threshold (e.g., 1.5°) based on the altitudeinformation obtained by the altitude information obtaining unit 56. Ifthe inclination degree of the field (headland) is determined to be equalto or less than the second threshold (No in step S101), the regionsetting unit 58 performs settings on the work region and the headlandsbased on the turning radius having been set by the work vehicle settingunit 36 and the traveling direction having been set by the travelingdirection setting unit 57. Namely, in this case, the possibility thatthe traveling body 2 may slide down on the headland is low, andtherefore any particular process such as increasing the headland widthis not performed. Rather, the settings on the work region and theheadlands are performed in a general manner. Then, the route generatingunit 35 generates an autonomous travel route P including linearautonomous work paths P1 arranged side by side in the work region andturning connection paths P2 arranged side by side in the headlands (stepS107).

Meanwhile, if step S101 determines that the inclination degree of thefield (headland) exceeds the second threshold (Yes in step S101), thedisplay control unit 31 of the wireless communication terminal 46 causesthe display 37 to display the inclined plane countermeasure settingwindow 82 (see FIG. 9) to inquire of the user as to if the user wishesto widen the headland as a countermeasure against slide-down of thetraveling body 2 (step S102).

If the user gives an instruction to widen the headland in response tothe inquiry in step S102 (Yes in step S102), the region setting unit 58obtains an increased headland width having been entered on the screen ofthe inclined plane countermeasure setting window 82 (or a preset valueobtained by a calculation appropriately performed to effectively preventthe slide-down) (step S103). After that, the procedure advances to stepS104.

Meanwhile, if the user does not give an instruction to widen theheadland in response to the inquiry in step S102 (No in step S102), theprocedure skips step S103 and advances to step S104.

In step S104, the inclination threshold determination unit 54 determineswhether or not the inclination degree of the field (headland) exceedsthe third threshold (e.g., 2°) based on the altitude informationobtained by the altitude information obtaining unit 56. If theinclination degree of the field (headland) is determined to be equal toor less than the third threshold (No in step S104), the region settingunit 58 performs settings on the work region and the headlands based onthe turning radius having been set by the work vehicle setting unit 36,the traveling direction having been set by the traveling directionsetting unit 57, and the headland width obtained in step S104. Namely,in this case, the field has a pitch inclination component that is equalto or greater than a certain level when viewed in the travelingdirection, and thus the traveling body 2 may potentially slide down onthe headland. Therefore, if the user gives an instruction to increasethe headland width, the settings on the work region and the headlandsare performed according to the increased headland width. The regionsetting unit 58 of the present embodiment applies the increased headlandwidth obtained in step S103 only to the headland on the down-side wherethe traveling body 2 may slide down by its own weight and depart outsidethe field with high probability. This can prevent the traveling body 2from departing outside the field even when the traveling body 2 slidesdown on the headland on the down-side.

Meanwhile, if step S104 determines that the inclination degree of thefield (headland) exceeds the third threshold (Yes in step S104), thedisplay control unit 31 of the wireless communication terminal 46 causesthe display 37 to display the inclined plane countermeasure settingwindow 82 as illustrated in FIG. 10 to inquire of the user as to if theuser wishes to change the turning radius as a countermeasure againstslide-down of the traveling body 2 (step S105).

If the user gives an instruction to change the turning radius inresponse to the inquiry in step S105 (Yes in step S105), the turningradius designating unit 59 obtains a changed turning radius having beenentered on the screen of the inclined plane countermeasure settingwindow 82 (or a preset value obtained by a calculation appropriatelyperformed to effectively reduce the slide-down) (step S106). After that,the procedure advances to step S107.

Meanwhile, if the user does not give an instruction to change theturning radius in response to the inquiry in step S105 (No in stepS105), the procedure skips step S106 and advances to step S107.

In step S107, the region setting unit 58 performs settings on the workregion and the headlands based on the increased headland width obtainedin step S103, the changed turning radius obtained in step S106, and thetraveling direction set by the traveling direction setting unit 57.Namely, in this case, the field has a pitch inclination component thatis relatively large when viewed in the traveling direction, and thusthere is a possibility that the traveling body 2 may slide down on theheadland. Therefore, if the user gives an instruction to increase theheadland width and an instruction to change the turning radius, thesettings on the work region and the headlands are performed according tothe increased headland width and the changed turning radius. Here, inthe present embodiment, the value preset in the box for entering thechanged turning radius on the inclined plane countermeasure settingwindow 82 is a value larger than the reference turning radius (minimumturning radius) specific to the model of the tractor 1. This can promptthe user to change the turning radius so that it has a larger value. Bychanging the turning radius to have a larger value, it is possible toreduce the centrifugal force applied to the traveling body 2 at the timeof turning, thereby making it possible to effectively prevent theslide-down. In addition, the route generating unit 35 generates theautonomous travel route P which includes the linear autonomous workpaths P1 arranged side by side in the work region and the turningconnection paths P2 arranged side by side in the headlands and withwhich the changed turning radius can be achieved (step S107).

According to the process described above, in a case where the autonomoustravel route P along which the tractor 1 performs autonomous travelincludes an inclination component (a difference of altitude) that isequal to or greater than a certain level when viewed in the travelingdirection, at least one of the widths (headland widths) of the headlandsin the traveling direction is increased and/or a turning radius is setlarger than the reference turning radius (minimum turning radius).Consequently, it is possible to generate an autonomous travel route Pwith higher safety in consideration of slide-down of the tractor 1.

Next, with reference to the flowchart in FIG. 13, the followingdescribes details of a process, performed by the control unit(autonomous travel control unit) 4, for reducing slide-down of thetraveling body 2 on the headland in a case where the field (specificregion) has an inclination component (a difference of altitude) that isequal to or greater than a certain level when viewed in the travelingdirection. FIG. 13 is a flowchart illustrating a process, performed bythe control unit (autonomous travel control unit) 4 of the tractor 1,for reducing slide-down of the traveling body 2 on the headland. In thetractor 1 of the present embodiment, the process illustrated in FIG. 13is repeatedly performed while the traveling body 2 is traveling alongthe connection path P2.

First, in step S201, the inclination threshold determination unit 50 ofthe control unit 4 reads out the detection result of the inertialmeasurement unit 53 to obtain the current inclination degree of thetraveling body 2, and determines whether or not the current inclinationdegree exceeds the first threshold. The inclination degree detected hereis an inclination determined based on a pitch angle and a roll angle.

If step S201 determines that the current inclination degree of thetraveling body 2 is equal to or less than the first threshold (e.g.,1.2°) (No in step S201), the possibility that the traveling body 2slides down greatly while traveling on the connection path P2 is low.Therefore, the control unit 4 does not perform any particular adjustmenton the vehicle speed, but controls the traveling body 2 to achieve thevehicle speed on the headland (second vehicle speed) having been set bythe work vehicle setting unit 36. Then, the control unit 4 continuouslymonitors the current inclination degree of the traveling body 2 (i.e.,repeatedly performs the determination in step S201).

If step S201 determines that the current inclination degree of thetraveling body 2 exceeds the first threshold (Yes in step S201), it canbe considered that there exists a relatively great inclinationcomponent, and hence the traveling body 2 may potentially slide down byits own weight. In this case, the control unit 4 controls the travelingbody 2 so that the vehicle speed of the traveling body 2 at the time ofturning becomes a vehicle speed (third vehicle speed) that is lower thanthe vehicle speed on the headland (second vehicle speed) having been setby the work vehicle setting unit 36. Consequently, the traveling body 2will make a turn at a lower speed. This can prevent the traveling body 2from sliding down greatly by its own weight at the time of turning.

According to the route generating system 99 of the present embodiment,the process of FIG. 12 is performed. Consequently, the region settingunit 58 performs the region setting (the settings on the work region andthe headlands) hardly causing slide-down of the traveling body 2 towardthe outside of the field, and the route generating unit 35 generates theautonomous travel route P hardly causing the slide-down of the travelingbody 2. FIG. 14 illustrates an example of the autonomous travel route Pgenerated by the route generating system 99 of the present embodiment.FIG. 14 is a view schematically illustrating the example of theautonomous travel route P generated by the route generating system 99 inconsideration of slide-down of the traveling body 2 on the headland. Inthe example in FIG. 14, the width L2 of the headland on the down-side inthe traveling direction has been increased (L1<L2), and the turningradius of the traveling body 2 on the headland on the down-side has beenset larger than a normally-used turning radius (i.e., a turning radiusset in a case where the field is not an inclined plane), as is clearfrom comparison with FIG. 5.

In addition, according to the autonomous travel system 100 that causesthe tractor 1 to perform autonomous travel along the autonomous travelroute P generated by the route generating system 99 of the presentembodiment, the traveling body 2 is caused to make a turn at a vehiclespeed that hardly causes slide-down of the traveling body 2. Asdescribed above, the present embodiment provides the countermeasuresagainst the slide-down of the traveling body 2 in various points.Consequently, it is possible to reduce the possibility that the tractor1 may slide down by its own weight and depart outside the field, therebyenabling safer autonomous travel than in the conventional system.

As described above, the route generating system 99 according to thepresent embodiment is configured to generate an autonomous travel route(route) P along which the tractor (work vehicle) 1 performs autonomoustravel. The route generating system 99 includes the work vehicle settingunit 36, the altitude information obtaining unit 56, the travelingdirection setting unit 57, and the region setting unit 58. The workvehicle setting unit 36 is configured to set vehicle information(specifically, a turning radius and/or the like) on the tractor 1. Thealtitude information obtaining unit 56 is configured to obtain altitudeinformation (inclination degree) on the field (specific region) wherethe autonomous travel route P is to be generated. The travelingdirection setting unit 57 is configured to set a traveling direction ofthe tractor 1 in the field. The region setting unit 58 is configured toset, in the field, a plurality of regions including a work region (firstregion) where autonomous work paths (routes) P1 being in parallel withthe traveling direction are generated and headlands (second regions)where connection paths P2 each connecting corresponding ones of theautonomous work paths P1 are generated. The region setting unit 58 setsthe widths of the headlands (headland widths) based on the vehicleinformation, the altitude information, and the traveling direction, thewidths of the headlands extending in parallel with the travelingdirection.

With this, the widths of the headlands are set in consideration of thealtitude information and the traveling direction. Therefore, forexample, in a case where at least one of the headlands has apitch-direction inclination when viewed in the traveling direction, itis possible to achieve the headland width determined in consideration ofslide-down of the tractor 1 that may occur while the tractor 1 is makinga turn on the headland. Consequently, it is possible to prevent thetractor 1 from departing outside the field.

In the route generating system 99 of the present embodiment, the regionsetting unit 58 sets the headlands respectively on first and secondsides of the work region in the traveling direction (work direction),and the region setting unit 58 sets, among the headlands on the firstand second sides, one of the headlands located on a lower side to have awidth L2 larger than a width L1 of the other of the headlands located ona higher side (L1<L2), based on the altitude information.

With this, for example, in a case where the specific region is aninclined field with two headlands having a difference of altitude, it ispossible to set a wider width for the one of the headlands on the lowerside, on which the weight of the tractor 1 is likely to be appliedtoward the outside of the field. Consequently, it is possible toeffectively prevent the tractor 1 from departing outside the field.

In addition, in the route generating system 99 of the presentembodiment, the work vehicle setting unit 36 sets, as the vehicleinformation, a turning radius of the tractor 1. In order that the regionsetting unit 58 sets the regions (e.g., the work region and theheadlands) and the route generating unit 35 generates the autonomoustravel route P, the work vehicle setting unit 36 sets, as the turningradius, a turning radius larger than a preset reference turning radius(minimum turning radius) based on the altitude information and thetraveling direction.

With this, in a case where at least one of the headlands has aninclination, a turning radius of the tractor 1 at the time of making aturn on the headland can be set larger. This makes it possible toprevent slide-down of the tractor 1.

In addition, the route generating system 99 of the present embodimentfurther includes the turning radius designating unit 59 configured toaccept, as the turning radius, designation of an arbitrary turningradius. In a case where the turning radius designating unit 59 acceptsthe designation of the arbitrary turning radius, the work vehiclesetting unit 36 sets, as the turning radius of the tractor 1, thearbitrary turning radius according to the designation.

In this manner, the user can designate the turning radius. Consequently,it is possible to take a countermeasure against the inclined planeindependently of the altitude information on the field and the turningcharacteristics of the tractor 1.

In addition, the autonomous travel system 100 disclosed in the presentembodiment causes the tractor (work vehicle) 1 to perform autonomoustravel along the autonomous travel route (route) P generated by theroute generating system 99 described above. In the autonomous travelsystem 100, the work vehicle setting unit 36 includes the vehicle speedsetting unit (not shown) configured to set the first vehicle speed ofthe tractor 1 in the work region (first region) and the second vehiclespeed of the tractor 1 on the headlands (second regions). The autonomoustravel system 100 further includes the control unit (autonomous travelcontrol unit) 4 configured to control autonomous travel of the tractor1. The control unit 4 controls, based on the altitude information, avehicle speed of the tractor 1 on the headlands to the third vehiclespeed, which is lower than the second vehicle speed.

With this, in a case where at least one of the headlands has a pitchdirection/roll-direction inclination, the vehicle speed of the tractor 1at the time of making a turn on the headland can be controlled to belower than a preset vehicle speed. This makes it possible to prevent theslide-down of the tractor 1.

The preferred embodiment of the present invention has been describedabove. However, the configurations described above can be modified asbelow, for example.

According to the embodiment described above, the altitude informationobtaining unit 56 obtains the altitude distribution information based onthe map data loaded to the wireless communication terminal 46.Alternatively, for example, it is possible to obtain transitions of theposture (a roll angle, a pitch angle, and a yaw angle) of the travelingbody 2 from the detection result of the inertial measurement unit 53observed when the tractor 1 is caused to travel around the field for thepurpose of setting the position and shape of the outer periphery of thefield, and to obtain (estimate) the altitude distribution information onthe field based on the transitions of the posture of the traveling body2 thus obtained. Further alternatively, the position informationobtained when the tractor 1 is caused to travel around the field may beconfigured to include not only latitude and longitude information butalso altitude information. Based on transitions of the positioninformation, the altitude information obtaining unit 56 may obtain thealtitude distribution information.

In the embodiment described above, the region setting unit 58 sets theregion (specific region) such that the width L2 of the headland on thedown-side in the traveling direction is larger than the width L1 of theheadland on the up-side in the traveling direction. However, this is notlimitative. Alternatively, for example, the headlands on the down- andup-sides may be widened to have the same width.

In the embodiment described above, the inclination thresholddetermination unit 50 uses the first threshold to determine theinclination degree of the traveling body 2, and the inclinationthreshold determination unit 54 uses the second and third thresholds todetermine the inclination degree of the inclination of the field. Thesethresholds may be different from each other, or may be the same value.In addition, the number of the thresholds is not limited to the numberin the embodiment described above.

In the embodiment described above, the turning radius designating unit59 may also accept, as a preset value, a turning radius smaller than thereference turning radius, for example, according to the user's entry onthe inclined plane countermeasure setting window 82. In a case where theuser sets a small turning radius (for example, a small turning radiusthat may potentially cause slide-down), it is preferable to generateconnection paths P2 in an autonomous travel route P to enable so-calledfish tail turning so that a turning radius is substantially set largeenough to prevent the slide-down.

The embodiment described above inquires of the user as to whether totake a countermeasure against the possibility of slide-down of thetraveling body 2 on the headland (specifically, as to whichcountermeasure to take, among increasing the headland width, changingthe turning radius, and both of them). However, this is not limitative.Alternatively, for example, a region setting with an increased headlandwidth and/or generation of an autonomous travel route P with a changedturning radius may be automatically performed.

According to the embodiment described above, the control of adjustingthe region setting (the setting on the headland width) and the turningradius and the control of adjusting the vehicle speed on the headlandare performed in parallel as a countermeasure against the possibilitythat the traveling body 2 may slide down on the headland. However, thisis not limitative. Alternatively, either of these controls may beperformed alone.

The description of the configuration described above has mainly dealtwith the control for preventing slide-down of the traveling body 2 in acase where the field has a pitch-direction inclination component whenviewed in the traveling direction. Alternatively, the autonomous travelroute P may be generated in consideration of slide-down of the travelingbody 2 in a case where the field has not only pitch-directioninclination component but also a roll-direction inclination component.In this case, for example, the roll-direction inclination degrees of theautonomous work paths P1 may be obtained based on the altitudedistribution information, and intervals between the autonomous workpaths P1 may be adjusted such that adjacent ones of the autonomous workpaths P1 do not overlap each other even when the traveling body 2 slidesdown in the work width direction. In other words, the autonomous travelroute P may be generated such that the autonomous work paths P1 arearranged each with an extra space left for the slide-down in the workwidth direction.

In the configuration described above, the work vehicle setting unit 36,the altitude information obtaining unit 56, the traveling directionsetting unit 57, and the region setting unit 58 are provided to thewireless communication terminal 46. However, these elements may beprovided to either of the tractor 1 and the wireless communicationterminal 46, and there is no particular limitation on this. Also,elements and configurations other than these elements may be provided toeither of the tractor 1 and the wireless communication terminal 46, too.

The route generating system 99 may be used only in the process ofgenerating a route in consideration of slide-down of the traveling body2 on an inclined plane, and actual traveling may be performed by theuser in such a manner that the user steers the tractor 1 while viewingthe generated route with the wireless communication terminal 46 or thelike, for example.

In the embodiment described above, it is determined whether or not acountermeasure against slide-down of the tractor 1 is necessary onlybased on the inclination degree of the field. However, this is notlimitative. Alternatively, for example, it may be determined whether ornot a countermeasure against slide-down of the tractor 1 is necessary inconsideration of the hardness and/or soil quality of the field inaddition to the inclination degree of the field.

The embodiment described above discloses setting a wide headland widthif it is determined, based on the altitude information, that the tractor1 may potentially slide down on the headland. However, this is notlimitative. Alternatively, for example, if there is a possibility thatthe tractor 1 may slide down on the headland, margins around theconnection paths P2 on the headlands may be set wider so that a headlandwidth becomes larger. In this case, a map representing a correspondencerelation between the inclination angle of (the headlands in) the fieldand the width of the margin may be prepared in advance, and the width ofeach margin may be determined according to the map.

REFERENCE SIGNS LIST

1 tractor (work vehicle)

36 work vehicle setting unit

56 altitude information obtaining unit

57 traveling direction setting unit

58 region setting unit

99 route generating system

P autonomous travel route (route)

P1 autonomous work path

P2 connection path

1-5. (canceled)
 6. A route generating system for generating a routealong which a work vehicle performs autonomous travel, comprising: awork vehicle setting unit to set vehicle information of the workvehicle; an altitude information obtaining unit to obtain altitudeinformation on a region where the route is to be generated; a travelingdirection setting unit to set a traveling direction of the work vehiclein the region, an inclination threshold determining unit for determiningwhether or not an inclination threshold value in the traveling directionis exceeded based on the altitude information and the travelingdirection; and a display unit for displaying a route setting screen forsetting the route, wherein when the inclination threshold determinationunit determines that the threshold value is exceeded, the display unitdisplays an inclined plane countermeasure setting window.
 7. The systemaccording to claim 6, wherein the system further includes a regionsetting unit for setting a plurality of regions including a first regionwhere a plurality of routes parallel to the traveling direction aregenerated and second regions where connection paths connecting theplurality of routes are generated, and the display unit displays ascreen capable of entering a width in a direction parallel to thetraveling direction in the second regions.
 8. The system according toclaim 7, wherein the work vehicle setting unit sets a turning radius ofthe work vehicle as the vehicle information, and the display unitdisplays a screen on which the turning radius is capable of beingentered when the inclination threshold determination unit determinesthat the threshold value is further exceeded.